Stabilization of CuII–I Bonds Using 2‐Benzoylpyridine Thiosemicarbazones – Synthesis, Structure, Spectroscopy, Fluo­rescence, and Cyclic Voltammetry. Issue 30 (23rd September 2015)

• Record Type: Journal Article
• Authors: Indoria, Shikha; Lobana, Tarlok S.; Singh, Deep; Kumari, Sangita; Kumari, Parveen; Bala, Tanu; Kamal, Ajar; Jassal, Amanpreet K.; García Santos, Isabel; Castineiras, Alfonso; Jasinski, Jerry P.
• Is Part Of: European journal of inorganic chemistry. Issue 30(2015)
• Page Start: 5106
• Page End: 5117
• Publication Date: 2015-09-23
• Subjects: Copper -- EPR spectroscopy -- Fluorescence -- Ligand design -- N, N, S li­gands; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201500618
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: The reactions of copper(I) iodide with N 1 ‐substituted 2‐benzoylpyridine thiosemicarbazones [(C6 H5 )(C5 H4 N)C 2 =N 3 –N 2 H–C(=S)–N 1 HR (R = Me, HL Me ; Et, HL Et ; Ph, HL Ph )] in acetonitrile/dichloromethane mixtures have formed the complexes [Cu2 II I2 (μ4 ‐N, N, S‐L Me )2 ] (1 ), [Cu II I(κ 3 ‐N, N, S‐L Et )] (4 ), and [Cu II I(κ 3 ‐N, N, S‐L Ph )] (7 ) through proton‐coupled electron transfer (PCET), and these complexes have rare Cu II –I bonds. The above thio ligands with copper(I) bromide and copper(I) chloride also formed similar Cu II –Br and Cu II –Cl bonds in complexes of stoichiometry [Cu II X(κ 3 ‐N, N, S‐L)] (L = L Me, L Et, L Ph, X = Br2, 5, 8 ; X = Cl3, 6, 9 ) by PCET. All of the complexes have been characterized by elemental analysis, infrared spectroscopy, electronic absorption spectroscopy, ESR spectroscopy, magnetic susceptibility measurements, molecular fluorescence, cyclic voltammetry, and single‐crystal X‐ray crystallography. The thio ligands coordinate as monoanionic N, N, S donors in1 –9 . The ESR data support the divalent oxidation state of the metal centers in the complexes, and the ESR parameters follow the trend g ∥ > g ⟂ > 2 with G values in the range 2–4, which suggests a d x 2 – y 2 ground state for the copper(II) complexes with variable exchange interaction in the solid complexes. The geometry around each copper(II) center is distorted square planar (mononuclear, 2 –9 ) or square pyramidal (dinuclear, 1 ). The stabilization of copper(II)–iodide bonds as well as the formation of Cu II –Br and Cu II –Cl bonds from thio ligands and copper(I) halides by a PCET process represents basic research of topical interest. Abstract : The direct reactions of N 1 ‐substituted 2‐benzoylpyridine thiosemicarbazones [(C6 H5 )(C5 H4 N)C 2 =N 3 –N 2 H–C(=S)–N 1 HR] with copper(I) halides form square‐planar or square‐pyramidal paramagnetic complexes with Cu II –I, Cu II –Br, and Cu II –Cl bonds through proton‐coupled electron transfer. For R = Et, complexes4 –6 are obtained.